Michigan Radio's MI Curious project puts our journalists to work for you: We investigate questions you submit about our state and its people.

One of the MI Curious questions was submitted by listener Justin Cross from Delton, Michigan. He asked: "What's the status of the Enbridge pipeline in the bottom of Lake Michigan running through the Straits of Mackinac?"

Michigan Radio's Mark Brush has been working to find an answer to the question. Brush says what he found is that Enbridge holds all the cards. The company is willing to talk, and they are aware of people's concerns.

Enbridge Energy has finished laying its new oil pipeline across Michigan as part of its $1.3 billion pipeline replacement project.

Much of the new pipeline was put in the ground near the old pipeline. That old line broke in 2010, spilling more than 800,000 gallons of heavy tar sands crude oil into Talmadge Creek and the Kalamazoo River. The company is just finishing cleanup work four years after that spill.

The company finished laying the new section of pipeline in St. Clair County and is taking the old Line 6B pipeline offline there.

This Week in Review Rina Miller and Jack Lessenberry discuss a plan to put a hold on the creation of new charter schools, Detroit mayor Mike Duggan’s idea for a new regional water authority, and Enbridge’s statement that it has fixed internal problems that lead to the 2010 Kalamazoo River oil spill.

Federal, state, and local agencies took part in a mock oil spill Wednesday in northern Michigan along the Indian River.

The emergency drill conjured memories of the 2010 Kalamazoo River oil spill. About a million gallons of crude oil have been cleaned up from that spill. There’s some concern about whether Enbridge has made important internal changes to avoid future pipeline problems.

Carl Weimer with the Pipeline Safety Trust said one of the reasons Enbridge failed to prevent the pipeline break near Marshall, Michigan in July 2010 is not because the company was completely unaware of corrosion and a cracks in the pipeline.

It wasn’t the real thing, but federal and state agencies joined with local groups to respond to a mock oil spill in northern Michigan today.

“That boom is to keep out any oil from coming on this side,” one of the coordinators told reporters, as he pointed at crews lowering pillow-like yellow floaters into the Indian River.

The booms were deployed just downstream from where an oil pipeline has sprung a make-believe leak. A short distance away, officials from a variety of agencies manned a full command center, organizing the response in the mock disaster drill.

There’s been a lot of controversy over TransCanada’s Keystone XL pipeline. But there’s another company working to bring more tar sands oil into the U.S.

Enbridge Energy wants to increase the amount of heavy crude oil crossing the border from the Alberta tar sands into the Great Lakes region.

Lorraine Little is with Enbridge. She says Enbridge wants to move more oil on its pipeline known as the Alberta Clipper. That pipeline runs about a thousand miles from northern Alberta to Superior, Wisconsin.

“Its purpose is to carry heavy crude oil from the oil sands in Alberta into our Superior terminal where then it can get off on other pipelines and serve refining markets around the Midwest region or other parts of the country,” she says.

Back in November of 2012, Enbridge filed an application with the U.S. State Department. The company wants to raise the capacity of the border segment of the Alberta Clipper pipeline to 800,000 barrels per day (they're currently transporting 450,000 barrels per day).

OXFORD, Mich. (AP) - A group that opposes expanding an underground oil pipeline in Michigan says two of its members are in custody after locking themselves to a truck belonging to a company involved with the project.

The Michigan Coalition Against Tar Sands says the men used bicycle U-locks on Monday to attach themselves by the neck to a truck at a Precision Pipeline storage yard in the Oakland County village of Oxford.

Spokesman Jake McGraw says firefighters cut the men loose after about 2 1/2 hours. He says sheriff's deputies were taking the protesters to jail.

Precision Pipeline is the primary contractor for expansion of the line owned by the Canadian company Enbridge Inc.

A section of the line ruptured in 2010, spilling more than 800,000 gallons of oil into the Kalamazoo River.

Michigan Attorney General Bill Schuette and the state Department of Environmental Quality have sent a warning letter to Enbridge Energy. It says the company has to do a better job of securing an oil pipeline that runs through the Straits of Mackinac.

“We just want to make sure that this pipeline’s going to be safe," said Dan Wyant, director of the DEQ. He says a leak in the pipeline would have implications throughout the Great Lakes.

“A lot of concern about this pipeline. Sixty years it’s been safe, but we’re in a position, Attorney General Schuette, I as the chief environmental officer of this state, to ensure we don’t have a problem on this pipeline,” he said.

Enbridge quickly responded it would add more anchors to its pipeline. Four years ago, a break in an Enbridge pipe dumped about a million of gallons of oil into the Kalamazoo River.

We've just marked the 25th anniversary of one of the most catastrophic man-made environmental disasters, the Exxon Valdez oil spill.

It was just after midnight on March 24, 1989 when the Exxon Valdez struck a reef in Prince William Sound. 11 million gallons of crude oil gushed into the pristine waters.

The clean-up effort was staggering. Among those called to help was U.S. Coast Guard Lt. Commander Thomas Haas. He was a chemist and an expert in hazmat cleanup. Twenty-five years later, that Lt. Commander is the president of Grand Valley State University.

That's what some in Michigan are undoubtedly thinking as they learn of a proposed natural gas pipeline that could run through Michigan on its way to Ontario, Canada.

The proposed Rover Pipeline would carry natural gas through about 180 miles of Michigan. Some of it would track the very same route as the controversial Enbridge 6B oil pipeline that was recently replaced.

Keith Metheny is a reporter with the Detroit Free Press.

Metheny said the pipes will take natural gas from areas in Pennsylvania, West Virginia, and Ohio and ship it westward into Michigan, through the southeast corner, spanning through six counties, and ending up in a hub in Ontario for distribution. The pipeline might follow a portion of the 6B route, around Oakland, Macomb, and St. Clair counties and possibly others.

“It’s going to be the very same people, the very same route, the people who saw their backyards torn up for a year, the people who occasionally had their roads inaccessible,” Metheny said.

Metheny said this pipeline would be large, 42 inches in diameter that will transfer more than 3 billion cubic feet of gas per day.

“In the highest gas demand day ever for Consumers Energy, which was in January 2013, they pushed out less natural gas across the entire state of Michigan than the amount that would pass through this pipeline every day,” Metheny said.

He added that the Federal Energy Regulatory Commission will determine if the pipes go down, but a decision may not be made until 2015.

Energy Transfer will hold a series of public meetings along the path of the proposed Rover Pipeline.

There will be a meeting this evening in Chelsea at 5:30 pm to 7:30 pm at the Comfort Inn Village Conference Center on Commerce Park Drive in Chelsea. And there's a meeting tonight in Richmond at the Lois Wagner Memorial Library, again, from 5:30 pm-7:30 pm.

A proposed natural gas pipeline could run through Michigan on its way to the Canadian border.

ET Rover, a subsidiary of Energy Transfer Partners, is planning a pipeline that would run through about 180 miles of Michigan. Some of it would track the same route as the controversial Enbridge 6-B pipeline that was recently replaced.

The company has sent out about 15,000 letters to landowners on and around the proposed line, asking for permission to do land surveys.

ET Rover will then submit a plan to the federal government for review. Vicki Granado is the company's spokesperson.

"It’s important to Energy Transfer that we reach out and communicate and meet people and we talk to them," said Granadao. "It’s also important that as we do work in these communities, that we are very respectful of people’s property and of all of the environmental concerns."

Jeff Insko is a landowner in Oakland County whose backyard was torn up for the Line 6B project.

"The prospect of having to go through it all over again is utterly demoralizing," said Insko. "People are disheartened and some of them are angry; some of them are stubborn and ready to fight."

ET Rover will hold an open house tonight in Fenton to update residents on the proposal.

A "who's who" of environmental groups say a 67-year-old pipeline in the straits of Mackinac could be a serious threat to the Great Lakes.

The pipeline is owned by Enbridge.

Howard Learner is head of the Environmental Law and Policy Center.

"It's an old aging pipeline," says Learner. "We can't afford to have happen in the Great Lakes what happened with the Enbridge pipeline and the oil spill in the Kalamazoo River. You know, it's already been a couple of years and we are still cleaning it up. "

In 2010, more than a million gallons of oil spilled into the Kalamazoo River after an Enbridge pipeline rupture.

Lerner's group, along with 16 other major environmental groups in Michigan, have sent a letter requesting an urgent meeting with Governor Snyder about the pipeline.

Learner says Enbridge may not be maintaining the pipeline properly, including not installing enough supports for the pipeline.

And he says the company may be sending oil through it under too much pressure, but there's no way to know until the state forces the company to disclose the information.

There's also a question whether state regulations written more than 60 years ago meet current standards.

*Correction - A previous version of this story said "more than a million barrels of oil spilled." It was more than a million gallons. Story corrected above.

TRAVERSE CITY, Mich. (AP) — Michigan's attorney general and chief environmental regulator have asked the company that owns two oil pipelines stretched beneath an ecologically sensitive area of the Great Lakes for evidence that the 61-year-old lines are properly maintained and in good condition.

Attorney General Bill Schuette and Dan Wyant, director of the state Department of Environmental Quality, posed a lengthy series of questions and requested stacks of documentation in a letter sent Tuesday to Enbridge Inc. and made public Wednesday. They said the pipelines, which run beneath the Straits of Mackinac — the waterway linking Lakes Huron and Michigan — pose a unique safety risk.

"Because of where they are, any failure will have exceptional, indeed catastrophic effects," their letter said. "And because the magnitude of the resulting harm is so great, there is no margin for error. It is imperative we pursue a proactive, comprehensive approach to ensure this risk is minimized, and work together to prevent tragedy before it strikes."

It’s been nearly four years since the Enbridge Energy oil spill. Enbridge has already recovered more than a million gallons of heavy tar sands oil from the Kalamazoo River. But federal regulators have ordered the company to clean up another 180,000 gallons that’s mixed in with sediment on the river bottom.

Now that spring is here, work is underway again.

Enbridge spokeswoman Jennifer Smith says dredge work is nearly finished on a section of river near Battle Creek. Workers will remove Ceresco Dam closer to Marshall this summer.

A trio of environmental activists will find out this week whether they will face prison time for a 2013 protest.

The three women were convicted in January of trespassing and obstruction charges. They and a fourth member of the group Michigan Coalition Against Tar Sands attached themselves to heavy machinery to protest the installation of a new oil pipeline near Stockbridge.

The four did not detach themselves after being ordered to by law enforcement officers during the 2013 incident.

Enbridge Energy is still cleaning up oil left over from its pipeline spill in the Kalamazoo River.

The company has already recovered most of the oil, but it's still working to comply with an order from the federal regulators, who say they need to clean up another 180,000 gallons.

According to Enbridge's new plan, they can start that cleanup March 15. But that's all dependent on this crazy weather. Right now, everything is frozen. But, if spring warms things up and there's flooding, that can also be problematic for the dredging process.

Enbridge Energy can move forward with plans to dredge thousands of truck loads worth of contaminated sediment from the Kalamazoo River - 135,000 cubic yards to be exact. The cleanup is related to the pipeline company’s 2010 oil spill.

On Monday night, Comstock Township’s planning commission unanimously approved the company’s plans to dredge. The heavy crude oil has broken down and mixed with the river sediment.

Enbridge was supposed to finish dredging contaminated river sediment a couple of months ago, but it failed to meet the deadline in part because the first set of plans it had in Comstock Township were rejected last summer.

The township said the operation was too close to homes and businesses, among other reasons.

About a dozen residents came to the meeting to raise specific concerns about pollution, smells and noise.

But in the end, the concerns were not enough to prevent the temporary operation in a district zoned for heavy manufacturing.

“I do think that this is the best site of all of the ones that we looked at with a minimum amount of impact,” Township Supervisor Ann Nieuwenhuis said. “And what’s most important is that the river is going to get clean.”

“All of the work will be done under the oversight of the federal and state regulators, and any comments or questions or concerns, we’ll do our best to address those as well," Enbridge spokeswoman Lorraine Little said after the vote.

Getting rid of the oiled sediment is key to meeting standards under the federal Clean Water Act.

Enbridge Energy has new plans to finish dredging oil from the Kalamazoo River spill in 2010. The spill was the biggest inland oil spill in U.S. history. The cleanup has cost the company more than a billion dollars so far.

The roughly 180,000 gallons of crude oil that was left on the river bottom before dredging began isn’t really oil anymore. It's tiny particles of weathered material that’s mixed in with sediment.

An Ingham County jury today convicted a trio of environmentalists on charges related to a 2013 protest.

Last July, the protesters attached themselves to equipment at an Enbridge oil pipeline construction site near Stockbridge. The protesters are opposed to the shipment of Canadian tar sands oil through Michigan.

They were charged with trespassing and obstruction after staying put after officers told them to leave.

Emergency unemployment benefits and senatorial "jitters" over an Enbridge oil pipeline running through the Straits of Mackinac: Both are issues consuming attention from Michigan's congressional delegation.

More than a week ago, a federal unemployment benefits program expired, leaving 1.3 million jobless Americans without aid. Some 45,000 of them are here in Michigan.

The program is the Emergency Unemployment Compensation program. In Michigan, the EUC added 36 more weeks to the state's regular 20 weeks of benefits.

On Capitol Hill today, Democrats are trying to pressure House Republicans to extend the program for three more months.

Meanwhile, the Obama administration is trying to ease concerns over an oil pipeline in the Straits of Mackinac.

Detroit Free Press Washington reporter Todd Spangler joins us now to tell us more about these issues.